Yo-yo having a user-adjustable clutch mechanism

ABSTRACT

The invention is a yo-yo in which at least one of the yo-yo&#39;s sides includes a user-adjustable clutch mechanism. The mechanism includes a cam and can be set by a user to cause the yo-yo, when it is spinning, to automatically return to a user&#39;s hand once the yo-yo&#39;s rotational velocity has decreased to a low level. A user can also set the mechanism to prevent the yo-yo from sleeping, or to enhance the yo-yo&#39;s ability to sleep at the end of the tether. A user-movable part of the clutch mechanism may be in the form of a knob or lever that extends from a side of the yo-yo.

FIELD OF THE INVENTION

The invention is in the field of user-manipulated toys. More particularly, the invention is an apparatus in the form of a yo-yo in which at least one of the yo-yo's side portions includes a user-adjustable clutch mechanism. The mechanism has three modes of operation: lock, auto-return and free-spin. In the lock mode, the yo-yo cannot “sleep” at the end of the tether and will readily return to the user's hand. In the auto-return mode, the yo-yo automatically returns to the user's hand when it is sleeping at the end of the tether and its rotational velocity decreases to a predetermined magnitude. In the free-spin mode, the yo-yo's ability to sleep at the end of tether is enhanced. The control unit for the clutch mechanism preferably includes a cam surface and a user-movable knob or lever located on a side surface of the yo-yo's side portion.

BACKGROUND OF THE INVENTION

Most yo-yos typically comprise two disk-shaped side portions that are rigidly connected to each other by some form of axle structure. The side portions are usually of unitary construction and may be made out of plastic, metal or wood. The axle structure is secured to the center of both side portions and can be an assembly of multiple parts, or merely be in the form of a dowel or a riveted pin. In many modern yo-yos, a bearing or other member is secured to, and has at least a portion rotatable on, a center portion of the axle structure.

The axle structure also forms an anchor for one end of a string-type tether. An end-located loop portion of the tether is positioned so that it encircles a center portion of the axle structure. The free end of the tether is usually tied to create a second loop portion that can be placed about one of a user's fingers to thereby temporarily secure the yo-yo to the user's hand.

When one end of the tether is secured to a user's finger and the remainder of the tether is wound about the axle structure, the yo-yo is ready for use. When the yo-yo is released, or thrown, from the user's hand, the yo-yo will begin to rapidly spin as it moves away from the user's hand. Once the tether is fully unwound, the yo-yo may “sleep” at the end of the tether, whereby the yo-yo's side portions continue to spin without the tether rewinding about the axle structure. Once the yo-yo is sleeping, there are a number of tricks, such as “walk the dog,” that a person can perform with the spinning yo-yo. A sleeping yo-yo is also often used to perform tricks that involve temporarily placing the spinning yo-yo onto a portion of the tether intermediate of the tether's two ends.

When a typical yo-yo is sleeping at the end of the tether and the user wishes to make the yo-yo return, the user will make a quick tug/jerk on the tether. This will result in a brief tightening of the tether, which is then automatically followed by a temporary slackening of the tether. Once the tether goes slack, the tether's twist will cause one or more portions of the tether located proximate the axle structure to move, and thereby contact, a spinning portion of the yo-yo. Once contact has occurred, the tether portion can become locked or otherwise engaged to the spinning portion of the yo-yo. Rotation of the spinning portion of the yo-yo will then cause the tether to wind about the axle structure, resulting in the yo-yo's return to the user's hand.

Every yo-yo has three crucial performance characteristics that determine the yo-yo's ability to perform tricks. They are the yo-yo's potential sleep time, its ability to return on command, and whether the yo-yo is smooth on the tether.

Concerning a yo-yo's sleep time, the longer the yo-yo can be made to sleep, the more time a user will have to complete any particular yo-yo trick. While some tricks can be performed quickly, others require a yo-yo that is capable of sleeping for a relatively long period of time.

Concerning a yo-yo's ability to return on command, this describes the yo-yo's ability to return to the user's hand when the user commands said return via an appropriate movement of the yo-yo's tether. For a yo-yo to return on command when it is sleeping, the structure and design of the yo-yo must be such that when the tether briefly goes slack, a portion of the tether can become locked to a spinning portion of the yo-yo. In most yo-yos, the ability for the tether to become locked to a spinning portion of the yo-yo is enhanced through the use of engagement adaptations, such as raised tether engagement members, located on the tether-facing surface of both of the yo-yo's side portions. The tether-facing surface of a side portion is herein defined as the surface of the side portion that faces a portion of the yo-yo's tether when said tether is taut and extends straight out from the yo-yo's string gap area. A yo-yo's string gap area is herein defined as the area located between the yo-yo's side portions. The ability of a yo-yo to return on command is also the common measure of a yo-yo's responsiveness.

Concerning a yo-yo's ability to be smooth on the tether, this refers to a yo-yo's ability, when it is sleeping at the end of the tether, to be temporarily placed on a medial portion of the tether without the tether becoming locked to a spinning portion of the yo-yo. An example of a trick that requires a yo-yo to be smooth on the tether is “man on the trapeze.” If, during such a trick, the yo-yo can slide on the tether, the yo-yo is said to be very smooth on the tether/string. The ability of a yo-yo to be smooth on the tether is favored when the yo-yo's responsiveness is low. A yo-yo with an overly high responsiveness will transform even the slightest contact between the tether and a spinning portion of the yo-yo into an inadvertent rapid return of the yo-yo to the user's hand. When such an inadvertent return occurs, the performance of a yo-yo trick will usually be cut short and thereby ruined.

Many beginner yo-yo players often have trouble getting the yo-yo to sleep, and then to return on command. For these players, there are prior art auto-return yo-yos that will readily sleep and include a clutch mechanism that automatically causes the yo-yo to return to the user's hand once the rotational velocity of the sleeping yo-yo decreases to a predetermined low level.

Caffrey teaches an auto-return yo-yo in his U.S. Pat. No. 4,332,102. The yo-yo's tether is non-rotatably secured to a bearing-spool rotatable on the yo-yo's axle pin. The yo-yo further includes a speed-sensitive centrifugal clutch that can engage an end portion of the bearing-spool when the yo-yo's rotational velocity decreases to a predetermined level. Once the bearing-spool is engaged by the clutch, the bearing-spool starts spinning with the yo-yo's side portions, thereby causing the tether to wind about the bearing-spool and the yo-yo to return to the user's hand.

Haines et al teach another auto-return yo-yo in their U.S. Pat. No. 6,354,905. In this patent, a bearing-spool similar to that shown in the Caffrey patent is employed and can be engaged by a centrifugal clutch mechanism. However, in the Haines et al yo-yo, a user can adjust the clutch mechanism via a recessed, rim-located screw that functions to position a gear-type clamp mechanism. Rotation of the screw can alter the rotational speed at which the yo-yo's clutch engages the bearing-spool. Rotation of the screw to its maximum extent in one direction will cause the clutch mechanism to continuously engage the bearing-spool, whereas rotation of the screw to its maximum extent in the other direction will lock the clutch mechanism in a position whereby it cannot engage the bearing-spool.

While satisfying a need, the prior art auto-return yo-yos have either limited adaptability, or are somewhat complicated and hard to adjust. This makes them undesirable for the non-beginner yo-yo player. For this reason, there is a need in the art for an auto-return yo-yo that can be easily and rapidly adjusted by a user, and can be employed by all skill levels of yo-yo players. Furthermore, there is a need in the art for an adjustable auto-return yo-yo that is durable and highly reliable via a relatively uncomplicated clutch mechanism.

SUMMARY OF THE INVENTION

The invention is a yo-yo that can be easily and rapidly adjusted to enable its use by all skill levels of users. The yo-yo features a plurality of different modes of operation that can be easily and accurately selected by a user without requiring the use of special tools. The different modes of operation can facilitate the learning and performance of various yo-yo tricks.

A yo-yo in accordance with the invention has a user-adjustable clutch mechanism located in at least one of its side portions. The yo-yo also includes a rotatable spool to which the yo-yo's tether is attached. The clutch mechanism functions via a selective locking of the spool to one of the yo-yo's side portions.

The clutch mechanism preferably features a plurality of weighted arms that are pivotally connected to one of the yo-yo's side portions and can engage the spool. Each of said arms can be positionally-locked, or be freely movable. When the clutch mechanism is set to a first mode of operation, the arms are continuously engaged to the spool, thereby enabling a speed-independent automatic return of the yo-yo. When the clutch mechanism is set to a second mode of operation, the arms are allowed to move and be affected by centripetal/centrifugal force arising due to the yo-yo's rotation, thereby enabling a speed-dependent automatic return of the yo-yo. When the clutch mechanism is set to a third mode of operation, each of the arms is maintained in a position where it is spaced away from the spool, thereby enhancing the yo-yo's ability to sleep at the end of the tether.

A clutch control unit is employed to control the operation of the clutch mechanism. The clutch control unit includes a user-movable portion that allows a user to set the clutch mechanism to any of the three previously described modes of operation. In a first embodiment of the invention, the user-movable portion of the clutch control unit is in the form of a rotatable knob located on the side of the yo-yo. In a second embodiment of the invention, the user-movable portion of the clutch control unit is in the form of a user-movable sliding lever/switch located on the side of the yo-yo. In both embodiments, the same side portion that has the user-movable portion of the clutch control unit also preferably includes indicia that facilitates a user's being able to properly position the user-movable portion to set the clutch mechanism for any of the three previously-described modes of operation.

The clutch control unit further comprises a cam in the form of a rotatable plate operatively connected to said user-movable portion. The plate features a pair of elongated slots, with each slot designed to inwardly receive a pin-type follower connected to one or the other of the clutch mechanism's pivotable arms. The slots have a shape that enables them to function as a cam surface for the followers. The user achieves selective operation of the clutch mechanism via causing the plate to be located in certain positions. As the plate is rotated, the followers slide in the slots, and their positions in said slots determine whether the arms are fixed in one of two locations, or are allowed to move.

A beginner yo-yo player would preferably set the clutch mechanism to its lock mode whereby the weighted arms continually engage the spool. The user can then learn the feel of the yo-yo and have the yo-yo instantly return whenever it is thrown.

Once the user becomes more familiar with the yo-yo, the clutch mechanism can be set to its automatic return mode. The user can then release the yo-yo, and the clutch mechanism will initially function to enhance the yo-yo's ability to sleep at the end of the tether. The user can then use the sleeping yo-yo to perform tricks, and the yo-yo will automatically return once it slows down to a point where it has just enough rotational momentum to enable it to fully rewind on the tether.

As the user becomes more proficient with the yo-yo, he or she can set the clutch mechanism to its free-spin mode whereby the clutch mechanism's weighted arms cannot engage the spool. The yo-yo can then be used to practice yo-yo tricks that require an extended period of sleep time and/or a low responsiveness. When the clutch mechanism is in either of the two latter settings, the yo-yo can still be made to return on command via an appropriate movement of the user's hand.

The invention is therefore a yo-yo that is uniquely, and easily, adaptable for use by yo-yo players of all skill levels. The yo-yo can initially be purchased to meet the needs of a beginning yo-yo player. Once the player's skills improve, the clutch mechanism can be adjusted to enable the yo-yo to be used for learning and performing advanced yo-yo tricks. For the advanced player, the ability to set the clutch mechanism in a free-spin mode can enable the yo-yo to be much smoother on the tether than most conventional yo-yos. The system employed to control the operation of the clutch mechanism is simple and is extremely easy, accurate and fast to adjust.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front, cross-sectional view of a first embodiment of a yo-yo in accordance with the invention. The yo-yo's clutch mechanism is shown in its lock mode.

FIG. 2 is a side view of the yo-yo shown in FIG. 1, taken at the plane labeled 2-2 in FIG. 1.

FIG. 3 is a side view of the yo-yo shown in FIG. 1, taken at the plane labeled 3-3 in FIG. 1. In this view, the disk portion of the clutch control unit is added and shown in phantom to facilitate viewing the interacting portions of the clutch mechanism.

FIG. 4 is an isometric front view of the yo-yo shown in FIG. 1, with the yo-yo shown in exploded fashion.

FIG. 5 provides a side view, similar to that shown in FIG. 3, but with the clutch control unit in a second position whereby the clutch mechanism is in its auto-return mode. In this view, a second position for the arms is shown in phantom.

FIG. 6 provides a side view, similar to that shown in FIG. 3, but with the clutch control unit shown in a third position whereby the clutch mechanism is in its free-spin mode.

FIG. 7 is a front, cross-sectional view of a second embodiment of a yo-yo in accordance with the invention.

FIG. 8 is a side view of the yo-yo shown in FIG. 7, taken at the plane labeled 8-8 in FIG. 7, and showing various internal parts in phantom.

DETAILED DESCRIPTION OF THE DRAWINGS

Looking now to the drawings in greater detail, wherein like reference numerals refer to like parts throughout the several figures, there is indicated by the numeral 1 a yo-yo in accordance with the invention.

The yo-yo 1 includes a first side portion 2 and a second side portion 4. The two side portions are connected together via an axle structure 6. The axle structure is preferably an assemblage of parts and comprises an axle pin 8 that has exterior threads 10 at each end and a longitudinal axis co-linear with the yo-yo's axis of rotation. Rotatably located on a center portion of the axle structure is a spool 12. A string-type tether 14 includes a loop portion 16 that encircles an exterior annular groove 20 of the spool. The tether's distal end (not shown) will normally be tied to create a loop to enable a temporary securement of said end to one of a user's fingers.

The spool 12 is preferably substantially cylindrical in shape and has first and second ends, 22 and 24 respectively. The center of the spool includes a thru-bore 26 through which the axle pin 8 extends. The diameter of bore 26 is slightly greater than that of the axle pin to thereby enable the free rotation of the spool on the axle pin. In the preferred embodiment, the spool is made of a plastic or metal material. The surface 28 that defines bore 26 may be coated with a lubricating and/or low-friction material, such as TEFLON, grease or graphite.

Located in a second exterior annular groove 30 of the spool is an o-ring 32. The o-ring is preferably made of a rubber or other relatively high-friction material and preferably extends outwardly from groove 30. It should be noted that groove 30 and o-ring 32 are optional. The spool may have, in place of groove 30, a continuous surface, or may include a coating of a high friction material in the area where the groove 30 is shown.

Side portion 2, shown on the right in FIG. 1, is an assemblage of parts and comprises a disk-shaped body member 34. Said body member is preferably made of a rigid, or substantially rigid, plastic material. Alternatively, the body member can be made of other materials, including metal, wood, rubber or be a composite or assemblage of rigid and/or non-rigid parts.

The body member 34 has a rim portion 36, a center-located thru-bore 40 and an inwardly-facing surface 42. Surface 42 may also be referred to as a tether-facing surface since it faces said tether when said tether is taut and is extending outwardly perpendicular to the yo-yo's axis of rotation. End 22 of the spool is received within the body member's thru-bore 40 in a manner whereby said spool does not normally contact the thru-bore's circular sidewall 44 due to the tether applying a centering force on the spool.

Located on surface 42 outwardly of thru-bore 40 are a plurality of optional tether-engagement members 50 that are oriented in a radially-directed manner and form a starburst-shaped array. Each tether engagement member protrudes from surface 42 in a direction toward said tether. The tether engagement members function to facilitate an engagement between the yo-yo's tether and the body member when a user manipulates the tether in a manner to cause the yo-yo to return on command. Other known types of surface adaptations that facilitate tether engagement in yo-yos, such as indentations, spaced pads/protrusions, the use of a material, such as rubber, that has a high coefficient of friction, may also be simultaneously or alternatively employed on, or in, surface 42.

The body member also features a large, outwardly-facing cavity 52. The cavity has a bottom surface 54 and a circular sidewall 56. Located in said cavity, and effectively dividing said cavity into two substantially equal portions, is a diametrically-extending elongated rib member 60 (note FIG. 2). Member 60 is preferably a separate part secured to said body member by an adhesive or by other conventional securement methods, such as fasteners. Alternatively, member 60 may be integrally formed in said body member.

The center of member 60 features a circular portion 62 that has a hexagonally-shaped cavity 64 and a thru-bore 66 collinear with the body member's thru-bore 40. Non-rotatably secured in cavity 64 is a hex nut 68. The hex nut forms a portion of the axle structure and features a thru-bore 70 that has threads complementary to the threads 10 located at each end of the axle pin. Attachment of the hex nut to a threaded end of the axle pin provides the means for securing side portion 2 to the axle pin.

The circular portion 62 of the rib member also includes two slots 72 that are located at its base proximate surface 54 of the cavity. The slots preferably have a square or rectangular shape.

Extending outwardly from surface 54 of cavity 52 are two pin members 74. Each pin member is preferably cylindrical in shape and is located near a different side of the rib member 60. The pin members are preferably integrally-formed portions of the body member, but may alternatively be separate pieces removably or permanently secured to said body member.

Pivotally connected to each pin member is a movable weight unit 76. Each weight unit comprises an elongated swing arm 80 and a weight 82.

Each of the swing arms has a thru-bore 84 at one end, and a cavity 86 at the other. The swing arms are pivotally connected to the body member via the pin members 74 fitting through the thru-bores 84. To enable the swing arms to move, each thru-bore 84 preferably has a diameter just slightly greater than the diameter of the associated pin member 74.

Non-movably secured in the cavity 86 of each arm is a weight 82. The weights 82 are preferably spherical in shape and are preferably made of a metal material.

One should note that each swing arm has an arcuately-shaped side surface 88 (note FIG. 3) that can engage the spool's o-ring 32. In this manner, the swing arms may also be considered to be spool engagement members.

Each weight unit is spring-biased toward the yo-yo's rotational axis via an associated coil spring 90. The coil springs are positioned whereby one end of each spring inwardly receives a prong portion 92 of one of the swing arms, while the other end of each spring is received in an associated complementary bore 94 in sidewall 56 of cavity 52.

Each swing arm also includes a follower member in the form of a cylindrically-shaped pin 96. The pin is located near the swing arm's weight 82 and extends in a direction away from the yo-yo's tether.

The circular portion 62 of the rib member 60 preferably also includes a ledge 98 onto which rests one end of a coil spring 100. The coil spring acts to outwardly bias a clutch control unit 102. Preferably, the distal end of portion 62 is capable of being received into a center bore 104 of the clutch control unit.

The clutch control unit 104 functions to control/determine the operation of the clutch mechanism and comprises a disk/cam portion 106 and a knob portion 108. Both of said portions are preferably made of a plastic or metal material.

The disk portion 106 is preferably in the form of a thin plate and functions as a cam through its employment of two substantially identical shaped slots 110. Each of said slots 110 has a first end 112, a second end 114 and a medially-located extension portion 116. The extension portion preferably has a slightly arcuate shape and extends in a direction toward the body member's rim. Each slot is designed to inwardly receive one of the pins 96. It should be noted that end 112 of each slot is at a slightly greater distance from the yo-yo's axis of rotation than is each slot's end 114. Also, the slot's side edges 118 form a cam-type guide surface for the follower member/pin 96.

Located proximate the periphery of the disk portion is a protuberance 120. The protuberance is preferably in the form of a half-hemisphere and extends in a direction away from the tether.

The clutch control unit's knob portion 108 provides a user-movable portion of the clutch control unit. The knob portion preferably has a knurled or ribbed side surface to facilitate grasping of said portion by a user's fingers. The knob further includes a position indicator, such as the arrow 122 shown in FIG. 2. Other forms of pointing/indicating structures, such as a large black dot on the end of the knob portion, or a single deeper groove in the body of the knob portion, may be employed in lieu of the arrow shown.

A round cap 124 fits over cavity 52. The cap is preferably transparent and is preferably secured to the body member via an interference-type fit between a peripheral edge 126 of the cap and the cavity's sidewall 56. Other well-known releasable or permanent securement methods for the cap may alternatively be employed.

The center of the cap includes an aperture 128 through which the knob portion of the clutch control unit extends. The cap's inwardly-facing surface 130 includes three spaced indentations 132, with each being complementary in size and shape to the protuberance 120 located on the clutch control unit's disk portion 106. The indentations are located whereby they can inwardly receive the protuberance 120 when the clutch control unit's disk portion is rotated to a position whereby said protuberance is adjacent one of said indentations 132.

Preferably located on an outwardly-facing surface of the body member's rim portion are first, second and third spaced j indicia, 134, 136 and 138 respectively. While shown located on the body member, the indicia may alternatively be located on the outer surface of the cap 124.

Side portion 4 of the yo-yo 1 preferably comprises a body member 140, a weight ring 142 and a cap 144. In the embodiment shown, side portion 4 has an outward appearance that is similar to side portion 2.

The body member 140 is in the form of a round disk and includes a cavity 146 located at the center of its tether-facing surface 148. The cavity is sized and shaped to inwardly receive end portion 24 of the spool 12. Preferably, the spool does not normally contact the body member.

The tether-facing surface 148 also preferably features a plurality of optional tether engagement members 50. The tether engagement members are oriented in the same manner as those of side portion 2, similarly extend toward the tether, and have the same functionality.

Body member 140 also includes a center-located thru-bore 150 and a peripherally-located rim portion 152. The rim portion encircles an outwardly-facing cavity 154 that has a bottom/rear surface 156 and a circular sidewall 160. Located at the center of the cavity is an outwardly-extending nipple portion 162 of the body member. Said nipple portion includes, at its distal end, a hexagonally-shaped cavity 164. A hex nut 68 fits into said cavity in a non-rotatable manner. A center-located thru-bore 70 of the hex nut includes interior threads that can engage the exterior threads 10 located on one end of the axle pin. In this manner, the hex nut can function to releasably secure side portion 4 to the axle pin, and forms a portion of the yo-yo's axle structure.

Weight ring 142 is located in cavity 154 and is fixedly secured to the cavity's sidewall 160, preferably via an interference fit. Alternatively, the weight ring can be secured by other permanent or releasable securement methods, such as via fasteners and/or adhesives. The weight ring is preferably made of a metal material and has a weight whereby the weight of side portion 4 will substantially equal that of side portion 2. In this manner, the yo-yo's two side portions will balance each other when the yo-yo is suspended from the tether. As a result, the yo-yo will not tend to lean toward one side or the other when the yo-yo is sleeping at the end of the tether.

Cap 144 functions to cover cavity 154 and may be permanently or releasably secured to body member 140. In the embodiment shown, a peripheral edge 166 of the cap is received in an annular groove 170 of the cavity's sidewall 160 and is a snap-fit into said groove.

It should be noted that adjacent each hex nut is a plug 172. The plug is non-rotatably fitted into the end of the cavity housing the hex nut 68. Located at the center of the plug is a bore 174 into which the end of the axle pin 8 is received. Preferably, the plug is made of a deformable material, such as nylon or rubber, that deforms as the axle pin's threads 10 engage the walls of the plug's bore. The plug may also be in the form of an annulus. The plug functions to provide a form of adjustable string gap whereby the axle pin's threads biting into the material of the plug act to positionally lock the axle pin and deter it from rotating relative to the plug. In this manner, the plugs bias against a rotation of either of the yo-yo's side portions relative to the other of the yo-yo's side portions. However, the plugs allow a user to rotate either side portion relative to the axle pin to thereby change the width of the yo-yo's string gap.

The yo-yo 1 can be used by any yo-yo player of any skill level. For a beginner, or a yo-yo player wishing to employ the yo-yo for the performance of certain looping tricks, he or she would preferably position the knob portion 108 so that arrow 122 is aligned with indicia 134. When so positioned, the clutch mechanism is in its “lock—no spin” mode.

The “lock—no spin” mode for the clutch mechanism is shown in FIGS. 1-3. When the clutch mechanism is in this mode, each swing arm 80 is locked in a first position by virtue of its pin 96 being located at end 112 of one of the slots 110 in the clutch control unit's disk portion 106. One should note that when the swing arms are in this locked position, they cannot pivot outwardly and the arcuately-shaped side surface 88 of each arm firmly contacts the spool's o-ring 32. As a result, the spool is locked to, and thereby forced to rotate with, side portion 2.

Since the spool must rotate with side portion 2, and the tether is preferably secured to the spool in a non-rotatable manner (while not shown, the end of the tether can be double-looped on the spool to ensure that the tether will not slip on the spool), the yo-yo is incapable of sleeping at the end of the tether. Whenever the tether fully unwinds from the spool, the tether is caused to rewind on the spool by virtue of the rotative momentum of the yo-yo's side portions and the tether's inability to slip on the spool. This enables a beginner yo-yo player to use the yo-yo in a basic manner, without having to worry about trying to get the yo-yo to return. For the more advanced yo-yo player, this mode of operation for the clutch mechanism facilitates the performance of looping tricks in which it is undesirable for the yo-yo to sleep at the end of the tether.

After a beginner yo-yo player has gotten the feel of the yo-yo, he or she will most likely want to set the clutch mechanism into its “auto-return” mode. This is accomplished by positioning the knob portion 108 of the clutch control unit whereby the arrow 122 is aligned with indicia 136. When the clutch mechanism is set in this mode of operation, shown in FIG. 5, each swing arm is free to pivot about its associated pin member 74. This is enabled by the pin 96 of each swing arm being located adjacent the associated slot extension portion 116, and being able to move into said slot portion 116.

When the yo-yo is not spinning, the coil springs 90 cause the swing arms to be located in the previously-noted first position (shown in solid in FIG. 5) in which each arm's arcuately-shaped side surface 88 contacts the spool's o-ring 32. This results in the spool being locked to side portion 2 and not being freely rotatable relative to the axle pin.

When the yo-yo is released, or thrown, from the user's hand and the side portions attain a considerable rotational velocity, centripetal force causes a radially-outward movement of the arms away from the yo-yo's spool, as they overcome the inward bias of the coil springs 90. The swing arms move to a second position (shown in phantom in FIG. 5) in which each of their arcuately-shaped side surfaces 88 are spaced from, and no longer contact, the spool's o-ring. This allows the spool to freely rotate on the axle pin, thereby enhancing the yo-yo's ability to sleep at the end of the tether.

Once the yo-yo slows down, the coil springs 90 overcome the outward force exerted on the swing arms due to the yo-yo's rotation, and function to move the swing arms inwardly, toward the yo-yo's axis of rotation. The swing arms will then move back to their first position in which their arcuately-shaped side surfaces contact the spool's o-ring. Once said contact occurs, the spool is again locked to side portion 2 whereby it is caused to spin with said side portion. This causes the tether to immediately wind about the spool, thereby effecting an automatic return of the yo-yo to the user's hand.

An advanced yo-yo player would most likely position knob portion 108 so that arrow 122 is aligned with indicia 138. In this position, shown in FIG. 6, the clutch mechanism is in its “free spin” mode of operation whereby each swing arm 80 is locked in a location whereby the arm's side surface 88 is spaced away from the spool's o-ring 32. Preferably, this is the same position for the swing arms as their previously noted second position, shown in phantom in FIG. 5. The outward movement of the arms is produced when the plate portion of the clutch control unit is rotated and the pins 96 travel within the slots 110. The side edges of the slots act as a cam surface and cause a radially outward movement of the pins as said pins reach end 114 of each slot. The outward movement of the pins causes a concomitant outward pivoting of the swing arms. Once the side surface 88 of each arm is spaced away from the spool's o-ring, the spool is capable of freely spinning on the axle pin.

When the yo-yo's clutch mechanism is in the “free spin” mode, the tether can unwind from the spool and the yo-yo will tend to sleep at the end of the tether. Since the spool is free-spinning, the yo-yo will continue to sleep until the user makes the yo-yo return on command by causing the tether to contact, and lockingly engage, one of the tether engagement members 50. In this manner, an experienced yo-yo player will be able to have the yo-yo return on command the same way as would be employed with a yo-yo that has the tether secured to a bearing located on a middle portion of the axle pin.

It should be noted that when the knob portion 108 is rotated from one position to another, a user can initially press the knob portion inwardly a short distance to disengage the control unit's protuberance 120 from one of the cap's indentations 132. Spring 100 biases the knob portion in an outward direction and allows said inward movement of the knob portion. Once disengaged, the knob can be rotated, and the protuberance allowed to enter one of the other indentations 132 to thereby lockably select a different mode of operation for the clutch mechanism. If the user does not press the knob inwardly, the knob can still be rotated, whereby the indentations 132, in combination with the protuberance, act as multiple detents/stops for the knob portion's movement.

FIGS. 7 and 8 show a second embodiment of a yo-yo 180 in accordance with the invention. Yo-yo 180 has side portions 182 and 4, wherein side portion 4 is identical to side portion 4 of the first embodiment, and side portion 182 is similar to side portion 2 of the first embodiment. Side portion 182 differs from side portion 2 in the design and support structure employed for the clutch mechanism's clutch control unit 184.

In the figures, one can see that the disk portion 186 of the clutch control unit has a finger portion 188 that includes a user-moveable lever 190. The lever is sized whereby a portion of said lever continually extends through an arcuately-shaped slot 192 in the side portion's cap 194 and thereby forms the user-movable portion of the clutch control unit. The finger portion 188 preferably has a shape and length whereby it inherently has a degree of resiliency and flexibility. Located proximate the end of the finger portion is a protuberance 120 that can be received within any of three complementary indentations 132 in the inwardly-facing surface 196 of the cap. As in the first embodiment, there are three indicia 134, 136 and 138 located on the body portion and aligned with the indentations. Each indicia is associated with a mode of operation of the clutch mechanism attainable when the finger portion is aligned with the particular indicia. In this manner, the indicia facilitate a user's ability to select any of the three previously described modes of operation of the clutch mechanism by positioning the finger member/lever adjacent the appropriate one of the three indicia.

It should be noted in FIG. 8 that the disk portion 186 of the clutch control unit is similar to the disk portion of the first embodiment, as it includes two shaped slots 110 that act as a cam or guide surface for the follower pins 96 of the swing arms. The disk portion of the clutch control unit is supported by a flat washer 200 located atop the circular portion 62 of the body member's rib member 60. A lubricating material, such as oil, grease or graphite, may be located between the surface of the washer and the adjacent surface of the disk portion.

The operation of yo-yo 180 is identical to that of yo-yo 1, except that a user slides the lever 190 within the slot 192 in lieu of turning an outwardly-extending knob portion of the clutch control unit. As the disk portion 186 rotates, the flexibility of the finger portion allows the user to disengage the protuberance 120 from one of the indentations 132 and then allows the protuberance to slide along the undersurface 196 of the cap and lock into another of the indentations 132. In this manner, the protuberance and indentations create a plurality of detents or stops for the rotation of the disk portion 186.

In either of the embodiments of the invention, one should note that the described clutch mechanism can be located in either, or both, of the yo-yo's side portions. While the described clutch mechanism has three modes of operation, it should be noted that any of said modes can be eliminated via an appropriate modification of the clutch control unit's slots 110. For example, the auto-return mode can be eliminated by deleting the slot's extension portion 116. Similarly, the lock or free spin modes can be eliminated through a deletion of the slot end portion 112 or 114 associated with each of said modes.

In addition, other forms, or shapes, of centripetal/centrifugal-actuated weight units can be used in lieu of the weighted swing arms shown. While both embodiments of the clutch mechanism are shown employing two swing arms, either embodiment may employ just a single swing arm, or any number of swing arms. Furthermore, the axle structure may be formed of other components than the ones shown in the figures.

The preferred embodiments of the invention disclosed herein have been discussed for the purpose of familiarizing the reader with the novel aspects of the invention. Although preferred embodiments of the invention have been shown and described, many changes, modifications and substitutions may be made by one having ordinary skill in the art without necessarily departing from the spirit and scope of the invention as described in the following claims. 

1. A yo-yo comprising: first and second side portions secured together in a spaced-apart relation by an axle structure; a spool secured to said axle structure in a manner whereby said spool is capable of rotating relative to said axle structure; a tether secured to said spool; a user-adjustable clutch mechanism that forms a portion of said first side portion, wherein said clutch mechanism comprises a movable weight, a clutch control unit, and a spool engagement member operatively connected to said weight and to said clutch control unit; wherein when said weight is in a first position, the spool engagement member engages said spool in a manner whereby said spool is locked to, and rotatable with, said first side portion, and wherein when said weight is in a second position, said spool engagement member is spaced from said spool whereby said spool is rotatable relative to said first side portion; wherein said clutch control unit has an operatively connected user-movable portion that can be moved by a user to either allow the spool engagement member to be moved via movement of the weight from said first position to said second position due to rotation of the first side portion, or to cause the spool engagement member to continually engage the spool, or to cause the spool engagement member to be continually spaced from said spool; and wherein said user-movable portion of the clutch control unit extends outwardly from said first side portion in a direction away from a tether-facing surface of the first side portion.
 2. The yo-yo of claim 1 wherein said clutch control unit further comprises a movable plate having a slot and wherein said spool engagement member has a follower portion that is received within said slot.
 3. The yo-yo of claim 2 wherein a side edge of said slot functions as a cam surface that engages said follower portion and can thereby cause an outward movement of said spool engagement member when the plate is rotated from a first position to a second position.
 4. The yo-yo of claim 1 wherein said second side portion includes a balance weight and weighs substantially the same amount as the first side portion.
 5. The yo-yo of claim 1 wherein said weight is spring-biased by a spring member toward a rotational axis of said yo-yo.
 6. The yo-yo of claim 1 wherein said spool engagement member is in the form of an elongated member that is pivotally secured at a first end to a body of the first side portion, and wherein said weight is secured to said elongated member proximate a second end of said elongated member.
 7. The yo-yo of claim 1 wherein the first side portion further includes a plurality of structures that act in combination with the clutch control unit to form a plurality of detents that cause the user-movable portion of the clutch control unit to stop whenever it is located in either a first position in which the clutch mechanism will function in a first predetermined manner or in a second position in which the clutch mechanism will function in a second predetermined manner that is different from said first predetermined manner.
 8. The yo-yo of claim 1 wherein a portion of the clutch control unit has a protuberance that can be located adjacent a portion of the first side portion that has a plurality of indentations, and wherein rotation of said clutch control unit can cause said protuberance to be received in one of said indentations to thereby create a locking engagement of said clutch control unit with said adjacent portion of the first side portion.
 9. The yo-yo of claim 1 further comprising first, second and third indicia located on the yo-yo's first side portion, wherein said indicia facilitates a user being able to position the clutch control unit to cause the clutch mechanism to act in a predetermined manner, whereby said first indicia indicates a position to which the user-movable portion of the clutch control unit should be moved to allow the weight to be moved from said first position to said second position due to a rotative movement of the first side portion, wherein said second indicia indicates a position to which the user-movable portion of the clutch control unit should be moved to cause the spool engagement member to continually engage said spool, and wherein said third indicia indicates a position to which the user-movable portion of the clutch control unit should be moved to cause the spool engagement member to be continually spaced from said spool.
 10. The yo-yo of claim 1 wherein said weight is a first weight, wherein said first side portion also comprises a second weight that can move from a first position to a second portion, wherein when said second weight is in said first position, a spool engagement member operatively connected to said second weight engages said spool, wherein when said second weight is in said second position, said spool engagement member operatively connected to said second weight will be spaced from said spool, wherein movement of said second weight from said first position to said second position can occur due to rotational movement of the first side portion.
 11. The yo-yo of claim 1 wherein the user-movable portion of the clutch control unit extends outwardly from a center portion of said first side portion.
 12. The yo-yo of claim 1 wherein the user-movable portion of the clutch control unit is in the form of a knob.
 13. The yo-yo of claim 1 wherein the user-movable portion of the clutch control unit is in the form of a lever that has at least a portion located whereby it is capable of being touched by a finger of a user.
 14. A yo-yo comprising: first and second side portions secured together in a spaced-apart relation by an axle structure; a spool secured to said axle structure in a manner whereby said spool is capable of rotating relative to said axle structure; a tether secured to said spool; a user-adjustable clutch mechanism that forms a portion of said first side portion, wherein said clutch mechanism can engage said spool in a manner whereby said spool will rotate with said first side portion; wherein said clutch mechanism comprises a movable weight, a spool engagement member operatively connected to said weight, and a clutch control unit; wherein when said weight is in a first position, the spool engagement member operatively engages said spool, wherein when said weight is in a second position, said spool engagement member is spaced from said spool and does not engage said spool; wherein said clutch control unit is operatively connected to said spool engagement member, has an operatively connected user-movable portion that extends outwardly from said first side portion, and has a cam portion having a guide surface to which is slidably engaged a follower member operatively connected to said spool engagement member, whereby when a user moves said user-movable portion in a predetermined manner, said guide surface will cause said follower member to also move in a predetermined manner; and wherein said clutch control unit can be set by a user to either allow the spool engagement member to be moved via movement of the weight from said first position to said second position due to rotative movement of said first side portion, or to cause the spool engagement member to continually engage the spool, or to cause the spool engagement member to be continually spaced from said spool.
 15. The yo-yo of claim 14 further comprising first, second and third indicia located on the yo-yo's first side portion, wherein said indicia facilitates a user being able to position the clutch control unit to cause the clutch mechanism to act in a predetermined manner, whereby said first indicia indicates a position to which the user-movable portion of the clutch control unit should be moved to allow the weight to be moved from said first position to said second position due to a rotative movement of the first side portion, wherein said second indicia indicates a position to which the user-movable portion of the clutch control unit should be moved to cause the spool engagement member to continually engage said spool, and wherein said third indicia indicates a position to which the user-movable portion of the clutch control unit should be moved to cause the spool engagement member to be continually spaced from said spool.
 16. The yo-yo of claim 14 wherein the first side portion further includes a plurality of structures that act in combination with the clutch control unit to form a plurality of detents that cause the user-movable portion of the clutch control unit to stop whenever it is located in either a first position in which the clutch mechanism will function in a first predetermined manner or in a second position in which the clutch mechanism will function in a second predetermined manner that is different from said first predetermined manner.
 17. The yo-yo of claim 14 wherein said weight is spring-biased by a spring member toward a rotational axis of said yo-yo.
 18. The yo-yo of claim 14 wherein the guide surface at least partially defines a slot, wherein at least one side edge of said slot forms said guide surface, and wherein said slot has a medial portion that extends toward a rim portion of the yo-yo's first side portion.
 19. The yo-yo of claim 18 wherein the slot has a first end and a second end and wherein said first end is closer to an axis of rotation of the yo-yo than is the slot's second end.
 20. The yo-yo of claim 14 wherein said weight is a first weight, wherein said guide surface is a first guide surface, wherein said spool engagement member is a first spool engagement member, wherein said first side portion also includes a second weight that can move from a first position to a second portion, wherein when said second weight is in said first position, the second spool engagement member engages said spool, wherein when said second weight is in said second position, said second spool engagement member will be spaced from said spool, wherein movement of said second weight from said first position to said second position can occur due to rotational movement of the first side portion, and wherein said clutch control unit includes another guide surface to which is slidably engaged a follower member operatively connected to said second spool engagement member.
 21. A yo-yo comprising: first and second side portions secured together in a spaced-apart relation by an axle structure to which a spool is rotatably secured, wherein said first side portion has a side surface that faces away from said second side portion; a tether secured to said spool; an adjustable clutch mechanism located in said first side portion, wherein a user can selectively set said clutch mechanism to operate in either a first, second or third mode of operation, wherein when said clutch mechanism is operating in said first mode, said clutch mechanism continually causes said spool to be locked to, and rotatable with, the first side portion, wherein when said clutch mechanism is operating in said second mode, said clutch mechanism will not cause said spool to be rotatable with the first side portion, and wherein when said clutch mechanism is operating in said third mode, said spool will be caused to rotate with said first side portion only when a movable weight associated with the clutch mechanism is in a predetermined position; and wherein said clutch mechanism includes a user-movable portion operatively connected to a cam that determines the mode of operation of the clutch mechanism, and wherein said user-movable portion extends outwardly from said side surface of the yo-yo's first side portion.
 22. A yo-yo comprising: first and second side portions secured together in a spaced-apart relation by an axle structure to which a spool is rotatably secured, wherein said first side portion has a side surface that faces away from said second side portion; a tether secured to said spool; an adjustable clutch mechanism located in said first side portion, wherein a user can selectively set said clutch mechanism to operate in at least two modes of operation, wherein when said clutch mechanism is operating in a first mode, said clutch mechanism continually causes said spool to be locked to, and rotatable with, the first side portion, and wherein when said clutch mechanism is operating in a second mode, said clutch mechanism will not cause said spool to be rotatable with the first side portion; and wherein said clutch mechanism includes a user-movable portion operatively connected to a cam that determines the mode of operation of the clutch mechanism, and wherein said user-movable portion extends outwardly from said side surface of the yo-yo's first side portion.
 23. A yo-yo comprising: first and second side portions secured together in a spaced-apart relation by an axle structure to which a spool is rotatably secured, wherein said first side portion has a side surface that faces away from said second side portion; a tether secured to said spool; an adjustable clutch mechanism located in said first side portion, wherein a user can selectively set said clutch mechanism to operate in at least two modes of operation, wherein when said clutch mechanism is operating in a first mode, said clutch mechanism continually causes said spool to be locked to, and rotatable with, the first side portion, and wherein when said clutch mechanism is operating in a second mode, said spool will be caused to rotate with said first side portion only when a movable weight associated with the clutch mechanism is in a predetermined position; and wherein said clutch mechanism includes a user-movable portion operatively connected to a cam that determines the mode of operation of the clutch mechanism, and wherein said user-movable portion extends outwardly from said side surface of the yo-yo's first side portion.
 24. A yo-yo comprising: first and second side portions secured together in a spaced-apart relation by an axle structure to which a spool is rotatably secured, wherein said first side portion has a side surface that faces away from said second side portion; a tether secured to said spool; an adjustable clutch mechanism located in said first side portion, wherein a user can selectively set said clutch mechanism to operate in at least two modes of operation, wherein when said clutch mechanism is operating in a first mode, said clutch mechanism will not cause said spool to be rotatable with the first side portion, and wherein when said clutch mechanism is operating in a second mode, said clutch mechanism will cause said spool to rotate with said first side portion only when a movable weight associated with the clutch mechanism is in a predetermined position; and wherein said clutch mechanism includes a user-movable portion operatively connected to a cam that determines the mode of operation of the clutch mechanism, and wherein said user-movable portion extends outwardly from said side surface of the yo-yo's first side portion. 